Food product comprising hydroxymatairesinol

ABSTRACT

A food product containing an effective amount of an active agent which is hydroxymatairesinol, a geometric isomer or stereoisomer thereof, or an acceptable salt thereof, or a mixture thereof, where the food product is selected from the group consisting of a nutritional supplement and a nutrient. The food product can increase the level of enterolactone or another metabolite of hydroxymatairesinol in a person&#39;s serum thereby causing prevention of a cancer or a certain non-cancer, hormone dependent disease in a person, based on the administration of hydroxymatairesinol to the person.

This application is a continuation of application Ser. No. 09/972,850,filed Oct. 10, 2001, now U.S. Pat. No. 6,689,809, which is acontinuation in part of application Ser. No. 09/829,944, filed Apr. 11,2001 and now abandoned, which is a continuation of application Ser. No.09/281,094, filed Mar. 30, 1999 and now U.S. Pat. No. 6,451,849.

FIELD OF THE INVENTION

This invention relates to methods for prevention of cancers, certainnon-cancer, hormone dependent diseases and/or cardiovascular diseases ina person, based on administering of hydroxymatairesinol to said person.The invention also concerns a method for increasing the level ofenterolactone or another metabolite of hydroxymatairesinol in a person'sserum thereby causing prevention of a cancer or a certain non-cancer,hormone dependent disease in a person, based on administering ofhydroxymatairesinol to said person. Furthermore, this invention relatesto pharmaceutical preparations, food additives and food productscomprising hydroxymatairesinol.

BACKGROUND OF THE INVENTION

The publications and other materials used herein to illuminate thebackground of the invention, and in particular, cases to provideadditional details respecting the practice, are incorporated byreference.

Lignans are defined as a class of phenolic compounds possessing a2,3-dibenzylbutane skeleton. They are formed by coupling of monomericunits called precursors such as cinnamic acid, caffeic, ferulic,coumaric, and gallic acids (Ayres and Loike, 1990). Lignans are widelydistributed in plants. They can be found in different parts (roots,leafs, stem, seeds, fruits) but mainly in small amounts. In many sources(seeds, fruits) lignans are found as glycosidic conjugates associatedwith fiber component of plants. The most common dietary sources ofmammalian lignan precursors are unrefined grain products. The highestconcentrations in edible plants have been found in flaxseed, followed byunrefined grain products, particularly rye. Mammalian lignan productionfrom different plant food are given in Table 1.

Considerable amounts of lignans are also found in coniferous trees. Thetype of lignans differs in different species and the amounts of lignansvary in different parts of the trees. The typical lignans in heart woodof spruce (Picea abies) are hydroxymatairesinol (HMR), α-conidendrin,conidendrinic acid, matairesinol, isolariciresinol,secoisolariciresinol, liovile, picearesinol, lariciresinol andpinoresinol (Ekman 1979). The far most abundant single component oflignans in spruce is HMR, about 60 per cent of total lignans, whichoccurs mainly in unconjugated free form. Lignan concentration in thickroots is 2–3 per cent. Abundance of lignans occur in the heart wood ofbranches (5–10 per cent) and twists and especially in the knots, wherethe amount of lignans may be higher than 10 per cent (Ekman, 1976 and1979). These concentrations are about hundred-fold compared to groundflax powder known as lignan-rich material.

The chemical structure of hydroxymatairesinol is

Lignans can be isolated e.g. from compression-wood fiber. These fibersoriginate from compression wood of stems and knots (oversize chipfraction) worsen the quality of paper (Ekman, 1976).

Plant lignans such as matairesinol and secoisolariciresinol, areconverted by gut microflora to mammalian lignans, enterolactone andenterodiol, correspondingly (Axelson et al. 1982). They undergo anenterohepatic circulation and are excreted in the urine as glucuronideconjugates (Axelson and Setchell, 1981). As an experimental evidence forthe chemopreventive actions of lignans, supplementation of a high-fatdiet with lignan-rich flaxseed flour (5% or 10%) or flaxseed lignans(secoisolariciresinol-diglycoside, SDG) prevented the development ofantiestrogen-sensitive DMBA-induced breast cancer in the rat (Serrainoand Thompson 1991 and 1992; Thompson et al. 1996a and 1996b). Theyreduced the epithelial cell proliferation, nuclear aberrations, thegrowth of tumors, and the development of new tumors. High lignan intakemay also protect against experimental prostate and colon cancers.Dietary rye (containing lignans), prevented at early stages the growthof transplanted Dunning R3327 prostatic adenocarcinomas in rats (Zhanget al. 1997; Landström et al. 1998). The percentage of animals bearingpalpable tumors, the tumor volume, and the growth rate weresignificantly lower. Further, flaxseed or SDG supplementation inhibitedthe formation of chemically induced aberrant crypts in rat colon(Serraino and Thompson 1992; Jenab and Thompson 1996). The antitumoraction may therefore be due to weak estrogen-antiestrogen-likeproperties and/or other mechanisms, which are not well understood.

Urinary excretion and serum concentrations of enterolactone are low inwomen diagnosed with breast cancer (Ingram et al. 1997; Hultén et al.1998) suggesting that lignans are chemopreventive. Mammalian lignans(enterolactone and enterodiol) have been hypothesized to modulatehormone-related cancers, such as breast cancer, because of theirstructural similarities to the estrogens. Enterolactone had weakestrogenic potency in MCF-7 cells (Mousavi and Adlercreutz 1992), buthad no estrogenic response in mouse uterine weight (Setchell et al.1981). As a sign of estrogen-like activity, SDG feeding during pregnancyand lactation to rats increased the uterine weight at weaning but theeffect was not evident at later stages (Tou et al. 1998). Possibleantitumor effects have also been associated with their antiestrogenicactions (Waters and Knowler, 1982). The inhibition of aromatase bymammalian lignan, enterolactone, would suggest a mechanism by whichconsumption of lignan-rich plant food might contribute to reduction ofestrogen-dependent diseases, such as breast cancer (Adlercreutz et al.1993, Wang et al. 1994). The potential antioxidant activity of lignanscould also represent a mechanism associated with the preventive actionof lignans in the development of cancers. Further, mammalian lignanshave shown to inhibit the conversion of testosterone to5α-dihydrotestosterone (DHT), the potent intracellular androgen, at theconcentrations which are achievable in humans (Evans et al. 1995). Thereduction in DHT concentration would modify the risk of prostate cancer(PC) and benign prostatic hyperplasia (BPH).

It is possible that lignans as precursors of enterolactone could alsoalleviate lower urinary tract symptoms (LUTS) and gynecomastia. On thebasis of the results obtained in the animal model, we have suggestedthat estrogens play an essential role in the development of the musculardysfunction involved in urethral dyssynergia seen as bladder neckdyssynergia or external sphincter pseudodyssynergia (Streng et al.unpublished observations). Such neuromuscular changes are at leastpartially reversed by an aromatase inhibitor (MPV-2213ad) indicating therole of estrogens. Further, gynecomastia, which is induced by exposureto estrogens or in the presence of increased ratio of estrogen toandrogens. Gynecomastia can be successfully treated with an aromataseinhibitor. The capability of lignans to inhibit 5α-reductase and/oraromatase combined with their potential antioxidant activity mayrepresent mechanisms associated with the preventive action of lignans inthe development of hormone-related diseases in male organism.

No data is available on the possible effects of lignans in humans. Thecurrent theories about lignan action in humans have been derived fromstudies on the effects of diets supplemented with flaxseed products (andthus lignans). Flaxseed in human female diet caused changes in menstrualcycle (Phipps et al. 1993). The subjects, all normally cycling women,showed a longer mean length of luteal phase and higherprogesterone/17β-estradiol ration in serum during the luteal phase whenthey took 10 g of flax seed powder/day in addition to their habitualdiets (Phipps et al. 1993). No significant differences between flax andcontrol cycles or concentrations of either estrone or 17β-estradiol werefound. Neither there were any significant differences between flax andcontrol groups for concentrations of serum estrogens in postmenopausalwomen (Brzezinski et al. 1997). Flaxseed supplementation increased SHBG(protein which binds estradiol with high capacity) concentration inserum. This is a typical estrogenic effect in the liver tissue.Increased SHBG concentration on the other hand reduces bioavailabilityof endogenous estrogens. In healthy young men, the short-term (6 weeks)flaxseed supplementation of the diet (10 g/d in muffins) had nosignificant effect on plasma testosterone concentrations (Shultz et al.1991) indicating a lack of estrogenicity in the male organism. Alltogether, these studies indicate that lignans may have weak hormonal(estrogenic and antiestrogenic) effects, but the mechanism of theiraction cannot be fully described by the hormonal effects.

In conclusion, isolated mammalian lignans have not been availableearlier in sufficient amounts to be used in animal experiments orclinical trials, and the only possibility to increase lignan intake hasbeen to increase the consumption of fiber-rich food items such asflaxseed. HMR or any other lignan that is efficiently converted toenterolactone, and can be produced/isolated in large quantities would bevaluable in the development of pharmaceutical preparations and foodproducts such as functional foods for chemoprevention of cancer andother hormone-related diseases and cardiovascular diseases.

SUMMARY OF THE INVENTION

According to one aspect, this invention concerns a method for preventionof a cancer, a certain non-cancer, hormone dependent disease and/or acardiovascular disease in a person comprising administering to saidperson an effective amount of hydroxymatairesinol, a geometric isomer ora stereoisomer thereof, or a salt thereof.

According to an other aspect, the invention concerns a method forincreasing the level of enterolactone or another metabolite ofhydroxymatairesinol in a person's serum thereby causing prevention of acancer or a certain non-cancer, hormone dependent disease in a personcomprising administering to said person an effective amount ofhydroxymatairesinol, a geometric isomer or a stereoisomer thereof, or asalt thereof.

According to a third aspect, the invention concerns a pharmaceuticalpreparation comprising an effective amount of hydroxymatairesinol, ageometric isomer or a stereoisomer thereof, or a pharmaceuticallyacceptable salt thereof, in combination with a pharmaceuticallyacceptable carrier.

According to a fourth aspect, the invention concerns a productcomprising hydroxymatairesinol, a geometric isomer or a stereoisomerthereof, or a salt thereof, in combination with a solid or liquidcarrier, for use as additive to a food product.

According to a fifth aspect, the invention concerns a food productcomprising an effective amount of hydroxymatairesinol, a geometricisomer or a stereoisomer thereof, or a salt thereof.

According to still one aspect, the invention concerns a method forincreasing the stability of a food product comprising the addition tosaid food product of an effective amount of hydroxymatairesinol, ageometric isomer or a stereoisomer thereof, or a salt thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the concentration-related inhibition of aromatase bylignans in JEG-3 cells.

FIG. 2 shows the proliferation of MCF-7 cells in the presence andabsence of HMR.

FIG. 3 shows the uterine wet weight of immature rats treated with HMR orwith an aromatase inhibitor.

FIG. 4 shows the antitumor activity of HMR against DMBA-induced mammarygland tumors in female rats.

FIG. 5 shows the excretion of enterolactone in the urine of rats treatedwith different doses of HMR.

DETAILED DESCRIPTION OF THE INVENTION

This invention relates to the use of a lignan, hydroxymatairesinol(HMR), for the prevention of cancer, non-cancer, hormone dependentdiseases and cardiovascular diseases by adding said HMR into food or byusing it as a pharmaceutical preparation. Surprisingly, HMR ismetabolized in vivo to enterolactone, which is assumed to account atleast partly for the antitumor properties of the lignans. Antioxidativeactivity of HMR in vitro is strong and this property indicates that HMRcan also prevent cardiovascular diseases through the protective effectagainst damaging free oxygen species in the body. The invention relatesalso to the use of HMR as a food additive to increase the food stability(i.e. inhibit lipid and pigment oxidations and vitamin losses whichcause loss of nutritional value and development of off-flavors in food).

The method according to this invention is particularly effective in theprevention of cancers such as breast cancer, prostate cancer and coloncancer, non-cancer, hormonal dependent diseases such as lower urinarytract symptoms, urethral dyssynergia, bladder instability, bladderoutlet obstruction, benign prostatic hyperplasia, and gynecomastia inmen, and cardiovascular diseases resulting from oxidized LDL in serum.

The pharmaceutical preparation according to this invention is preferablyan oral formulation. The required amount of the active compound (HMR)will vary with the particular condition to be prevented. A typical doseranges from about 10 to about 100 mg per day and adult person. Typicaldosage forms include, but are not limited to, oral dosage forms such aspowders, granules, capsules, tablets, caplets, lozenges, liquids,elixirs, emulsions and suspensions. All such dosage forms may includeconventional carriers, diluents, excipients, binders and additives knownto those skilled in the medicinal and pharmaceutical arts.

The pharmaceutical carriers typically employed may be solid or liquid.Thus, for example, solid carriers include polysaccarides such aslactose, sucrose, gelatin, agar, while liquid carriers include aqueoussolutions of salts, polysaccarides, complexing agents, surfactants,syrups, vegetable oils such as peanut oil or olive oil, and certainalcohols. However, any pharmaceutically acceptable solid or liquidcarrier can be used in the pharmaceutical preparation according to theinvention, except that the formulation cannot be a mixture of only theactive agent and plain water.

In the food additive of the invention, the carrier to be used, can beany non-toxic solid or liquid carrier acceptable for use in food andsuitable to be admixed with HMR without affecting the properties of HMR.The role of the material is mainly to make the exact dosage of HMReasier. A suitable concentration is for example 100 mg to 1 g of HMR per100 g of carrier. Typical dosage forms include, but are not limited to,oral dosage forms such as powders, granules, capsules, tablets, caplets,lozenges, liquids, elixirs, emulsions and suspensions. All such dosageforms may include conventional carriers, diluents, excipients, bindersand additives known to those skilled in the art.

Typical solid carriers include polysaccarides such as lactose, sucrose,gelatin, agar, while liquid carriers include aqueous solutions of salts,polysaccarides, complexing agents, surfactants, syrups, vegetable oilssuch as peanut oil or olive oil, and certain alcohols. However, anyacceptable solid or liquid carrier can be used in the food additiveaccording to the invention, except that the food additive formulationcannot be a mixture of only the active agent and plain water.

The food product according to this invention is especially a functionalfood, a nutritional supplement, a nutrient, a pharmafood, anutraceutical, a health food, a designer food or any food product. Asuitable concentration of HMR in the food product is, for example, 1 to20 mg of HMR per 100 g of food product.

The functional food according to this invention can, for example be inthe form of butter, margarin, biscuits, bread, cake, candy,confectionery, yogurt or an other fermented milk product, or cereal suchas muesli.

The addition of hydroxymatairesinol is particularly useful to increasefood stability in the meaning of inhibitition of lipid, vitamin andpigment oxidations, which cause loss of nutritional value anddevelopment of off-flavors in food. A suitable concentration of HMR forthis purpose is, for example, about 0.1%.

Isolation of HMR for use in this invention can be made from oversizechip fraction (containing branches, twists and knots) of compressionwood. According to a preferred embodiment, the hydroxymatairesinol isderived from coniferous wood. It has been shown that hydroxymatairesinolis the dominant lignin in coniferous wood. For example, in knotrichspruce wood 85% or even more of the lignins is hydroxymatairesinol.

The properties of HMR were studied by seven different assays:

-   1. Measurement of antioxidant capacity in vitro-   2. Measurement of aromatase inhibiting capacity in JEG-3 cells-   3. Measurement of estrogenic and antiestrogenic activity in MCF-7    cell cultures-   4. Evaluation of estrogenic and antiestrogenic activity by uterine    growth bioassay-   5. Measurement of estrogenic and antiestrogenic activity in adult    male rats-   6. Investigating the antitumor activity in rat DMBA-induced mammary    cancer model-   7. Analysis of metabolites from rat urine after different doses of    HMR

The isolation and purification of HMR in sufficient amounts forbiological tests has been impossible earlier because it is a componentof wood lignans, which have been relatively poorly characterized.Understanding the distribution of HMR in different parts of spruce(Ekman 1976 and 1979) has given the opportunity to study lignans andespecially HMR in detail.

A linear correlation was found between the doses of HMR and the amountsof urinary enterolactone. Enterolactone is a well known mammalian lignanformed by intestinal bacteria from matairesinol or by oxidation ofenterodiol (Axelson and Setchell 1981; Axelson et al. 1982). Only minuteamounts of unmetabolized HMR and other metabolites (enterodiol and7-hydroxyenterolactone) were found in urine. Their amounts remainedunchanged when the daily dose of HMR was increased. These findingssuggest that HMR was metabolized to enterolactone, and, further,enterolactone derived from HMR through demethylation and dehydroxylationsteps is not converted to enterodiol. Based on the structure of HMR onehad expected that 7-hydroxyenterolactone were the main metabolite ofHMR, but this was not the case. This hydroxyl group is eliminated in themetabolism. The metabolism of HMR differs from that of SDG. SDG ismetabolized to enterodiol which is partly oxidized to enterolactone(Rickard et al. 1996; Lampe et al. 1994). HMR thus offers an advantageover SDG as a direct precursor of enterolactone.

HMR had weak if any estrogenic action in rat uterus or in the maleorganism. It exerted weak but not significant estrogen-like activity inMCF-7 cells. No antiestrogenic activity was demonstrated for HMR.Therefore, it is surprising that it had highly significant antitumoractivity in DMBA-induced tumor model in rats as shown in FIG. 2. Theactivity of HMR may be due to HMR itself or to enterolactone. However,no dose-dependence was found in the chemopreventive action of HMR whengiven in two different doses (3 and 15 mg/kg) to rats afterDMBA-treatment. Thus HMR needs not to be converted to enterolactone tohave an antitumor effect or smaller doses of these lignans aresufficient to accomplish the maximal chemopreventive effects.

HMR is very effective antioxidant as shown in Tables 2 and 3. It is oneof the most potent known inhibitors of lipid peroxidation and excellentinhibitor of LDL oxidation. Inhibition of LDL oxidation is considered tobe of special importance in humans as the concentration of oxidized LDLin serum is considered to be one of the best predictors ofcardiovascular diseases such as atherosclerosis. HMR may serve as a foodadditive to increase the food stability (i.e. inhibit vitamin, lipid andpigment oxidations which cause loss of nutritional value and developmentof off-flavors in food), because HMR was much better superoxide anionscavenging and peroxyl radical scavenging agent than well knownantioxidants butylated hydroxyanisol (BHA) and butylated hydroxytoluene(BHT), which are commonly used for increasing the food stability.

Experiments

Chemicals

Various lignans were tested in vitro for their estrogenicity,antiestrogenicity, capability to inhibit aromatization and for theirantioxidative properties. The test compounds were purchased from thefollowing sources: enterodiol and enterolactone from Plantech, London,UK, and 7-hydroxyenterolactone containing two 7-OH enantiomers was agenerous gift from Dr. Kristina Wähälä, Department of Applied Chemistry,University of Helsinki, Finland.

Extraction of HMR from Wood

HMR extracts were isolated from Norway spruce (Picea abies) as describedby Ekman, 1976 and Ekman 1979. Shortly, freeze-dryed ground heartwoodwas Soxhlet-extracted in with hexane to remove non-polar lipophilicextractive. The wood sample was re-extracted in the same apparatus withacetone/water (9:1 v/v) to give crude lignans. Hydroxymatairesinol (HMR)and its isomer were isolated and re-chromatographed with XAD-resin forfurther purification.

Measurement of Antioxidant Capacity In Vitro

The antioxidative capacity of lignans was estimated by four differentmethods: 1) inhibition of lipid peroxidation, 2) inhibition of lowdensity lipoprotein (LDL) oxidation, 3) superoxide anion scavenging and4) peroxyl radical scavenging assays.

Inhibition of lipid peroxidation was evaluated on the basis of theirpotency to inhibit tert-butylhydroperoxide-induced lipid peroxidation(t-BuOOH-LP) in rat liver microsomes in vitro (Ahotupa et al. 1997). Thetest for the t-BuOOH-LP was carried out as follows: The buffer (50 mMsodium carbonate, pH 10.2, with 0.1 mM EDTA) was pipetted in a volume of0.8 ml in the luminometer cuvette. Twenty microliters of diluted livermicrosomes, final concentration 1.5 mg protein/ml, was added, followedby 6 ml of luminol (0.5 mg/ml) and test chemicals. The test compoundswere added to incubation mixtures in a small volume diluted in ethanolor dimethylsulphoxide (2% of incubation volume), and the lipidperoxidation potency was compared to that of the vehicle (ethanol ordimethyl sulphoxide). The reaction was initiated by 0.05 ml of 0.9 mMt-BuOOH at 33° C. Chemiluminescence was measured for about 45 min at 1min cycles, and the area under curve (integral) was calculated.Chemiluminescence measurements were carried out using a Bio-Orbit 1251Luminometer (Bio-Orbit, Turku, Finland) connected to a personal computerusing dedicated software for the assays.

Inhibition of LDL oxidation was estimated as described by Ahotupa et al,1996. Shortly: LDL was isolated by precipitation with buffered heparin.After resuspendation in phosphate buffer, 20 mM CuCl₂ was added and themixture was incubated for 3 hrs at +37° C. After this, LDL lipids wereextracted with chloroform-methanol, dried under nitrogen, redissolved incyclohexane and analyzed spectrophotometrically at 234 nm. The intensityof absorbance is indicative of LDL oxidation. To test the ability ofdifferent compounds to prevent LDL oxidation, the compounds were addedto the incubation mixture prior addition of CuCl₂. Possible interferenceof test compounds with the assay procedure was excluded by measuring theabsorption at 234 nm before and after the incubation period. For thosecompounds which showed antioxidative potency at the startingconcentration (0,1 mM), IC-50 values (i.e. concentrations at which testcompound inhibited LDL oxidation by 50%) was determined.

Superoxide anion scavenging method was based on the superoxide anionproduced in controlled conditions by xanthine-xanthine oxidase systemand detection of the generated reactive oxygen species by luminometer(Ahotupa et al., 1997). The ability of test compounds to decrease thechemiluminescence was evaluated. IC-50 concentration (concentrationwhich prevented the chemiluminescence by 50%) was calculated.

Peroxyl radiocal scavenging assay was based on generation of peroxylradicals by thermal decomposition of 2,2′-azobis(2-amidinopropane)HCland their detection by chemiluminescence (Ahotupa et al., 1997). Theresults were calculated as the stochiometric factor, i.e. how many molesof peroxyl radicals can be scavenged by one mole of the test compound.

Measurement of Aromatase Inhibiting Capacity in JEG-3 Cells

The effects of HMR and structurally related lignans (enterolactone,enterodiol and 7-hydroxyenterolactone) were studied on formation of³H-17β-estradiol from ³H-andostenedione in JEG-3 cells, humanchoriocarcinoma cell line. The JEG-3 choriocarcinoma cells are a usefularomatase model enabling the study of aromatase inhibition in vitro(Krekels et al 1991). Cells were maintained in DMEM containing 10% fetalcalf serum (FCS). The incubation mixture contained 50 μl³H-androst-4-ene, 3,17-dione (0.5 nM), 50 μl unlabelled androstenedione(0.5 nM), 100 μl test compounds (10 mM) and 800 μl cell suspension (1million cells). After the incubation for 4 h, unlabelled carriers(androstenedione, testosterone, 17β-estradiol and estrone) were added.The steroids were extracted twice with 3.0 ml dichloromethane. HPLC wasused for separation and quantification of the radiolabelled³H-17β-estradiol as previously described (Mäkelä et al. 1995). Thecolumn system consisted of a guard column followed by a C18 150×3.9 mmID analytical column (Technopak 10 C18 HPLC Technology; WellingtonHouse, Cheshire, UK). The mobile phase was acetonitrile/water (35/65)and the flow rate was 1.2 ml/min. For in-line detection of theradioactive metabolites, the eluent of the HPCL column was continuouslymixed with liquid scintillant and then monitored with in-lineradioactivity detector.

Measurement of Estrogenic and Antiestrogenic Activity in MCF-7 CellCultures

The MCF-7 cell line (human breast cancer cells) stock cultures weregrown in phenol red free RPMI medium supplemented with 5% FCS, 100 U/mlpenicillin and 100 μg/ml streptomycin, 10 μg/ml insulin and 1 nM17β-estradiol in T-75 cell culture bottles. The medium was replaced withfresh ones three times per week. The stock cultures were harvested bytrypsinization and suspended in 10 ml phenol red free versene solutionand cenitifuged for 5 min 800 rpm. The cell pellet was carefullyresuspended into RPMI medium supplemented with 5% dextran charcoalstripped FCS (dcFCS) and seeded on 6 well plates 50 000 cells/3.0 mlmedium/well. On the second day of culture the medium was changed andtest compounds were added. To test the estrogenicity of the lignancompounds, they were diluted in ethanol and added to cell cultures infinal concentration of 1.0 M. In each proliferation assay 1.0 nM17β-estradiol solution in ethanol was used as a positive control forestrogenic response. Equal amounts of ethanol were added to controlwells. To test the antiestrogenicity both 17β-estradiol and lignansolutions were added to cell cultures. The cells were cultured for 5 to7 days in the presence of test compounds, and the medium was changedevery second day. Cell proliferation was quantified by counting thereleased nuclei with Coulter counter.

Evaluation of Estrogenic and Antiestrogenic Activity in Immature RatUterotropic Test

The estrogenicity HMR was evaluated by the uterotropic assay in immaturerats which was performed as described earlier (Jordan et al. 1977), withthe exception of treatment time which was 7 days instead of 3 days inthe reference study. The treatment time was longer because of theexpected weak estrogenicity of the test compound. The treatment ofimmature rats with an aromatase inhibitor (MPV-2213 ad), which preventsbiosynthesis of estradiol, was used as a methodological control fornon-estrogen-stimulated uterus.

Evaluation of Estrogenic and Antiestrogenic Activity in Adult Male Rats

Estrogenic (antiandrogenic) and antiestrogenic effects of HMR werestudied in intact and hypoandrogenic Noble strain male rats (age 6–9month), correspondingly. The chronic hypoandrogenic state with bothstructural and functional changes in the male reproductive tract wasinduced by neonatal estrogenization (diethylstilbestrol, 10.0 μg/kg bodyweight in rape oil s.c. on postnatal days 1–5). These changes are knownto be partly reversible by aromatase inhibitor treatment consistingdaily dose of MPV-2213 ad 10–30 mg/kg body weight (Streng et al.unpublished observations).

Animals were fed the soy-free basal diet (SDS, Whitham Essex, England)and they had a free access to water. Twelve of both intact andhypoandrogenic animals were cavaged in daily dosage of HMR 50 mg/kg bodyweight in rape oil. Another twelve animals from both animal models werecavaged with rape oil only as a placebo treatment. After four-weektreatment the animals were sacrificed. The weights of testis andaccessory sex glands (ventral prostate, seminal vesicles and coagulatinggland) were measured. Serum and testis testosterone and pituitary andserum luteinizing hormone (LH) levels were measured by immunoassays(Haavisto et al. 1993).

Investigating the Antitumor Activity in Rat DMBA-induced Mammary CancerModel

Antitumor activity of HMR in rat mammary cancer was studied as describedearlier (Kangas et al. 1986). Fifty-day-old female Sprague-Dawley ratswere given 12.0 mg DMBA (dimethylbentz[a]anthracene) by cavage. Afterapproximately 6 weeks palpable tumors could be detected, whereafter thewidth (w) and the length (1) of the tumors were measured once a week todetermine the tumor volumes according to a formula V=(πw² l)/12. Therats were also weighed once a week. The rats were allocated in 3different groups so that the total number of tumors in the beginning ofthe experiment was similar in each group: (1) Control group 8 animals,(2) HMR 3.0 mg/kg 7 animals, and (3) HMR 15.0 mg/kg 7 animals, one ofwhich had to be killed before the end of the experiment.

HMR was given per os starting 9 weeks after the DMBA-induction, i.e. 3weeks after palpable tumors appeared, and was given daily for 7.5 weeks.At the end of the experiment the tumors were classified in groupsaccording to their growth pattern: 1. Growing tumors (PD=progressivedisease); 2. Non-growing, stabilized tumors (SD=stabilized disease, nochange in tumor volume or regression less than 75%; 3. Regressing tumors(PR=partial response, regression of tumor volume more than 75%); 4.Disappeared tumors (CR=complete response, no palpable tumor).

Analysis of Metabolites from Rat Urine Receiving Different Doses of HMR

Ten Sprague—Dawley male rats (age 4 month) were used to study themetabolism of HMR in vivo. Animals were housed in pairs with 12 hlight:dark cycle and had free access to water and soy-free basal diet(SDS, Whitham Essex, England) during the metabolism study.

Rats were cavaged with HMR dissolved in 10% ethanol in PEG in doses 3,15, 25 and 50 mg/kg body weight once a day for two days. After secondcavaging the 24 hour urine was collected in metabolic cages incollection jars containing 120 μl 0.56 M ascorbic acid and 120 μl 0.15 MNa-azide as preservatives. The centrifuged urine volumes were measuredand stored in −20° C. For pretreatment 750 μl 0.2 M acetate buffer (pH4.0±0.1) was added to 3.0 ml thawed urine aliquots. Sep-Pak C18 columns(100 mg silica based resin/column) were used for urine extractions.Columns were preconditioned with 3.0 ml H₂O, 3.0 ml methanol and 3.0 mlacetate buffer. After urine had filtered through the column and washedwith 3.0 ml of acetate buffer polyphenolics were eluted with 3.0 mlmethanol. The eluate was evaporated to dryness under nitrogen in +45° C.water bath and dryed residues were redissolved in 3.0 ml of 0.2 Macetate buffer. 30 μl Helix pomatia enzyme mix was added and thesolutions were incubated in +37° C. to hydrolyze both glucuronides andsulfates. 300 μl of flavone stock solution (100 μg/ml in EtOH) was addedinto hydrolyzed samples. The samples were extracted in C-18 columns andevaporated to dryness as described above and stored in −20° C. untilanalyzed with GC-MS.

The evaporated urine samples were dissolved in pyridine, and silylatedby adding BSTFA:TMCS (10:1) silylation reagent. The GC-MS analyses ofthe silylated samples were performed with an HP 6890-5973 GC-MSinstrument. The GC column was an HP-1 crosslinked methyl polysiloxanecolumn (15 m×0.25 mm i.d., 0.25 μm film thickness). Helium was used ascarrier gas at a flow of 1 ml/min. The GC-oven was temperatureprogrammed from 60° C. to 290° C., at 8° C./min heating rate. TheGC-injector was set in split-mode at a split ratio of 1:15. The injectortemperature was 250° C. Compound identifications were based on massspectra. The quantitative calculations were based on uncorrected peakareas of target components relative to the internal standard.

Results

Assessment of Antioxidant Capacity In Vitro

HMR had stronger lipid peroxidation capacity than any other lignan orflavonoid in our tests (Table 2). HMR was compared to well knownantioxidants TROLOX, which is a water soluble vitamin E derivative, andBHA and BHT in the ability of inhibiting lipid peroxidation, inhibitionof LDL oxidation, and scavenging superoxide and peroxyl radicals (Table3). HMR was as a whole the strongest antioxidant, more effective thanBHA or BHT in all assays, and stronger than TROLOX in all assays exceptfor lipid peroxidation inhibition assay, where the compounds were almostequally active.

Aromatase Inhibiting Capacity in JEG-3 Cells

The inhibition of ³H-17β-estradiol formation from ³H-androstenedione inJEG-3 cells was tested at different concentrations of HMR. Theinhibitory capacity of HMR was compared to enterolactone,7-hydroxyenterolactone and enterodiol. Enterolactone caused adose-dependent inhibition of aromatization within the concentrationrange of 1.0 to 10.0 μM. It was further shown that enterodiol wasnoninhibitory indicating that the lactone ring is critical for theinhibition. 7-hydroxyenterolactone and hydroxymatairesinol had noinhibitory effects (FIG. 1) indicating the importance of the number andlocation hydroxyl groups in the lignan molecule for the aromataseinhibition.

Estrogenic and Antiestogenic Activity in MCF-7 Cell Cultures

HMR had very weak, not statistically significant estrogenic orantiestrogenic activity in MCF-7 cell proliferation assays as shown inFIG. 2.

Evaluation of Estrogenic and Antiestrogenic Activity in Immature RatUterotropic Test

FIG. 3 illustrates the effects of HMR on the uterine growth of theimmature rats. HMR had no significant estrogenic effect on the uterineweight gain of the immature rats. Neither did HMR reduce the weightgains indicating no antiestrogenic effect. Aromatase inhibitor preventedthe increase of uterine weight, as expected, indicating that the methodfor the measurement of the aromatase inhibitors was adequate.

Evaluation of Estrogenic and Antiestrogenic Activity in Adult Male Rats

After a 4-week treatment with HMR, no significant changes in the weightsof accessory sex glands and testis were observed in control andhypoandrogenic animals (Table 4). There were no significant changes intestosterone or LH concentrations, either (Table 5). These resultsindicate, that HMR is not a full estrogen agonist in male organism,because it does not exert the typical estrogenic activity onhypothalamus—hypophysis—gonad—axis (inhibition of LH and androgensecretion). Neither is HMR an antiestrogen because it does not reversethe changes induced by neonatal estrogenization in the male rat.

Investigating the Antitumor Activity in Rat DMBA Induced Mammary CancerModel

Number of growing (PD) versus stable (SD) tumors, regressing (PR) tumorsand disappeared (CR) tumors is presented in FIG. 4. The antitumor effectof HMR was found to be statistically very significant. There was noclear dose-dependency of antitumor action in this model. Bothantioxidative and tumor growth regressing properties of HMR maytherefore be connected with the in vivo antitumor activity. Themechanism of antitumor activity of HMR in vivo is still unknown.

Analysis of Metabolites from Rat Urine After Different Doses of HMR

FIG. 5 illustrates that the main excreting metabolite of HMR in rats isenterolactone, which may be the biologically active compound. This issurprising taking into account the chemical structure of HMR, becauseone would expect hydroxyenterolactone to be the main metabolite. Themetabolism of HMR to enterolactone may be catalyzed by bacterialintestinal flora rather than by the rat liver.

CONCLUSIONS

Hydroxymatairesinol (HMR) has antitumor activity either as unchangedcompound and/or after conversion to enterolactone in DMBA induced breastcancer model. HMR has therefore a potential to have beneficial effectsin humans who are at risk of developing breast cancer (BC), prostatecancer (PC), colon cancer or benign prostatic hyperplasia (BPH). HMR ismetabolized to enterolactone which inhibits aromatization in vitro. HMRmay as a precursor of aromatase inhibitor also prevent the developmentof lower urinary tract symptoms (LUTS), bladder instability, bladderoutlet obstruction, urethral dyssynergia, and gynecomastia. HMR has alsostrong antioxidative activity and may therefore be used as food additive(antioxidant). HMR as pharmaceutical product or dietary supplement mayhave advantageous cardiovascular effects in humans. Addition of HMR tofood to make innovative new functional food, nutraceutical, health food,pharmafood, designer food or novel food is feasible.

It will be appreciated that the methods of the present invention can beincorporated in the form of a variety of embodiments, only a few ofwhich are disclosed herein. It will be apparent for the specialist inthe field that other embodiments exist and do not depart from the spiritof the invention. Thus, the described embodiments are illustrative andshould not be construed as restrictive.

TABLE 1

Production of mammalian lignans from different plant food by in vitrofermentation with human fecal flora.

μg/100 g FLAXSEED FLOUR 68 000 SOYBEAN 170 CEREAL BRANS: WHEAT 570 OAT650 WHOLE CEREALS: RYE 160 POTATO 80 CARROT 350 ONION 110 ¹Thompson etal. Nutrition and Cancer 16:43–52, 1991

TABLE 2 ANTIOXIDANT PROPERTIES OF LIGNANS AND SOME RELATED FLAVONOIDS INVITRO BY LIPID PEROXIDATION INHIBITION TEST. Antioxidative capacity(t-BuOOH-LP) Compound IC₅₀ (μM) Flavonoids kaempferol 0.9(3,4′,5,7-tetrahydroxy- flavone) quercetin 0.4(3,3′,4′,5,7-pentahydroxy- flavone) kaempferide 0.5(3,5,7-trihydroxy-4′-methoxy- flavone) Lignans enterolactone 15.92,3-bis-(3′-hydroxybenzyl)-butyrolactone enterodiol 12.72,3-bis-(3′-hydroxybenzyl)-butane-1,4-diol hydroxymatairesinol 0.08

TABLE 3 COMPARISON OF ANTIOXIDATIVE EFFECTS OF HMR AND KNOWNANTIOXIDANTS IN VITRO. IC-50 concentrations have been presented, exceptfor peroxyl radical scavenging assay where the stochiometric factor(i.e. how many moles of peroxyl radical one mole of test compound canscavenge). HMR¹ TROLOX² BHA³ BHT⁴ Inhibition of lipid 0.06 μM 0.02 μM1.1 μM 15.3 μM peroxidation Inhibition of LDL  2.0 μM  2.7 μM notdetermined oxidation Superoxide anion  5.6 μM   25 μM  15 μM   >1 mMscavenging Peroxyl radical 1:4 1:2 not determined scavenging¹hydroxymatairesinol ²water soluble E-vitamin derivative ³Butylatedhydroxyanisol (synthetic antioxidant) ⁴Butylated hydroxytoluene(synthetic antioxidant) Determination methods have been described in thetext.

TABLE 4 The effect of four week exposure to HMR on male rat reproductiveorgan relative weights¹ Ventral Seminal Coaculating Body weight TestisProstate vesicle gland Treatment n g mg/kg body weight Intact animalsPlacebo 12 426 ± 28 4362 ± 170 909 ± 146 412 ± 43 223 ± 49 HMR 12 447 ±38 4223 ± 304 938 ± 148 419 ± 59 204 ± 48 50 mg/kg HypoandrogenemicPlacebo 12 481 ± 29 3340 ± 509 333 ± 188 249 ± 63  69 ± 49 animals HMR12 455 ± 36 3276 ± 327 378 ± 198 266 ± 49  70 ± 30 50 mg/kg ¹Data isexpressed as mean ± SD (mg/kg body weight). Relative weights after HMRtreatment are not significantly different from placebo in either group.

TABLE 5 The effect of four week exposure to HMR on male rat testosteroneand LH concentrations¹ Testis Serum testosterone testosterone PituitaryLH Serum LH Treatment n (ng/testis) (ng/ml) (μg/pit) (ng/ml) Intactanimals Placebo 12 97.6 ± 46.3 2.405 ± 1.122 6.747 ± 2.479 1.804 ± 1.29450 mg/kg HMR 12 112.9 ± 58.5  2.770 ± 1.421 6.838 ± 2.061 1.088 ± 0.352Hypoandrogenic Placebo 12 63.5 ± 25.9 1.197 ± 0.663 8.673 ± 2.224 0.712± 0.371 animals 50 mg/kg HMR 12 48.0 ± 15.2 0.939 ± 0.431 7.530 ± 2.2860.854 ± 0.333 ¹Data is expressed as mean ± SD. Hormone concentrationsafter HMR treatment are not significantly different from placebo ineither group.

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1. A food product comprising an effective amount of an active agentwhich is hydroxymatairesinol, a geometric isomer or stereoisomerthereof, or an acceptable salt thereof, or a mixture thereof, whereinthe food product is selected from the group consisting of a nutritionalsupplement and a nutrient.
 2. The food product of claim 1, wherein saidactive agent has been derived from coniferous wood.